Electronic absorption spectra of HXeCl, HXeBr, HXeI, and HXeCN in Xe matrix

The electronic UV absorption spectra of thermal reaction products H-Xe-Y (Y = Cl, Pr, I, or CN) have been measured in solid Xe at 12 K. The spectra ar e obtained after the annealing of an extensively irradiated matrix doped wi th an HCl, HBr, HI, or HCN precursor. The spectral assignment is based on t he correlation between the UV spectra and the known infrared absorptions of these compounds. An analysis of the annealing behavior of the UV absorptio ns due to H-Xe-Y, Y/Xe and H/Xe yields a quantitative estimate that 20-30% of the photogenerated Y is converted to H-Xe-Y. Present multireference conf iguration interaction (MRCI) calculations provide strong support that the s pectral observations are due to the A (1)Sigma <-- X (1)<Sigma> transitions of H-Xe-Y. The spectral width of the absorptions indicate that the transit ions are from a bound ground state to a repulsive excited state.